Heated scraping tool



March 30, 1954 w. G. STOLK 2,673,395 HEATED SCRAPING TOOL Filed July 5, 1849 2 Sheets-Sheet 2 al Es lEz nfar W/LL/AM G 57044 Patented Mar. 30. 1954 UNITED STATES PATENT 0F F ICE l 2,673,395

HEATED'SCRAPING TOOL William G. Stolk, Riverside, Ill., assignor of onethird' to Lawrence E. Spotswood, La Grange,

.one -sixth .to. Robert J;;Newman,;Brookfie1d,land one-sixth towFrancis W. Anderson, Berkeley, Ill.

Application July 5, 1949, Serial-No; 103,092

l Claim.

This invention relates to improvements in scraping-tools. "More particularly,-it has to do with a scraper in which the bladeis heated by an element insidethe casing of the-scraper in order *thatheat can be applied by the blade at the point at which two materials arebondedtogether and thus expediteseparation of the-ma- ---terials-during the scraping operation.

The under surfaces of "various metal body -members of--modernautomobiles are coatedtwith an asphalt base mastic for protection against cor-ros-ion and for-sound deadening purposes. 'This coating may be as much as a half inch in thickness depending upon the part to which it is=applied-. When body members, such-as fenders, are creased or dented-it is -necessary to firstre- =-move=the coating of mastic which forms a cushioning' layer and prevents accurate working of --.the metal. --Heretofore the-mastichas been r-=-- movedseither by applying-a blow torch directly "to-the mastic or bydirecting the flame of the torch against the opposite-side-ofthe fender. In -eachcase, the temperature of the-'mastic is brought up to the melting point so that. the coating- Will-tend to flow'off the metal. Theappliecation of- -anopen flame to the mastic material gives rise to-a dangerous fire hazard, since many of thesematerials are infiammablaand gasoline vapors-oftenare present in the atmosphere in body shops. Further, both methods are relatively n inefficient, andscraping often is required to 0b- -taina-- clean surface. Finally, these methods-are -obiectionable from the-viewpoint-ofthe mechanic because of the evolution of irritating fumes and "the"dza'fnger of skin burns from the molten mastic.

-It therefore an important object of this in- Wention to-provide an apparatus for removing a mastic-material from a backing surface without incurring the danger of fire orof burns from hot, molten mastic.

A further obgect of this invention is to provide a scraping tool that heats the mastic material only-momentarily as the scraping edge contacts said material.

Another-object of this invention is the provi -sion of"a scraping tool having a blade that is heatedfbycontact' with an electricallyheated ele- "ment.

Afurther object of this invention is'the provision of a scraping tool having a removableblade secured-in an insulated casing.

Although the heated scraping tool ofthis invention is particularly useful for removing sound 'prooiing'ma-stic from the under-surface of body ymeinbers of a automobile, it-is to beunderstood that the toolis not limitedto such usage it being generally useful for separating two materials which are adhesivelysecured.together -and at least one of which'is softenable upontheapplication of heat. For example, an obvious use of this novel tool is inthe removal of inlaid linoleum from afloor.

Other andfurther features, objects, andusages of thescr-aping tool of this invention will. become apparent to one skilled in the: art from thefollowing detailed description takenin connection with the accompanying drawings.

On the drawings:

Figure 1 is a perspective viewvof ascraping tool constructed according. to the teachings ofithe present invention.

Figure 2' is a side elevational view, partly "in verticalsection, of the scrapingtool of Figural, showing a handle bent intov a substantially. horizontal position.

Figure 3 is a horizontal on line III-III of Figure 2.

Figure 4 is a fragmentary top plan View of a modified form of the scraping tool of. the present invention. 7

Figure 5 isa fragmentary verticalesectional view taken on line VV of Figure4. a

Figure 6 is a top plan View of. a second modisectional view taken I fication' ofthescraping tool of the present. in-

vention.

Figure 7 is a vertical sectionalyiew taken on lineVII-JIII of Figurefi.

As shown on the drawings: In Figure l the reference numeral l-fl represents a scraping head connected by a pair of arms l2 to. a wooden handle l3. Each arm includes a bent strap portion I5 secured. by setscrews Hi to the head I0 and a. semi-cylindrical portion "(Figure 3) thatextends through an elongated axial passage l8-in the handle [3. The semi-cylindrical portions H ofthe armsareinconfronting,

abutting relation defining a tubular passage through the handle It. :Spring clips 20.are dis posed in annular grooves (not shown) in the semitrio heating element 33. This heating element may be of any commercial type adapted to heat the base member 22 by contact therewith. While the cavity in the base member 22 is illustrated as having a boxlike configuration, it is to be understood that this cavity can be of any configuration depending on the shape of the heating element that is used. In other words, the walls of the cavity can assume the configuration of the heating element so that there will be a maximum amount of contact area between the element and the base and consequently a maximum amount of heat transfer to the base member 22.

The closure plate may, if desired, bear down against the heating element to hold it in place. It will be understood that this closure plate may be constructed of an insulating material so that the heat from the element 33 will be directed toward the forward edge of the base member 22.

The base member 22 may be made of steel or any other material having a capacity for conducting heat from the element-contacting surface to the scraping edge 34. As shown in Figure 3, the scraping edge 34 may be of a slightly arcuate configuration to increase the emciency of the scraper in difficult positions.

The heating element 33 is connected to a source of electric energy by leads 36 and 31 which pass through a rubber grommet 38 positioned in an aperture 39 in the rear wall of the closure plate 28 and through the tubular passage in the handle [3 to an insulated connector plate 4| (Figure 3) which is secured by setscrews 42 to the handle 13. A portion 44 (Figure 2) of the handle i3 is removably mounted on the handle by screws 46 over the insulating connector plate 4!. It will of course be understood that the cap portion 44 has a partially hollowed-out interior to accommodate the connector screws it and a rear aperture through which leads 4'! and 48 ex tend.

In practice, a plug mounted on the ends of the leads 4'! and 48 is connected to a source of electric energy. The heating element 33 becomes hot and, due to its contact with the base member 22, causes this member including the blade edge 34 to become hot.

When the hot edge 34 is pressed against the mastic as the scraping tool is moved along, the mastic is heated at the point where it adheres to the backing plate. his instantaneous heating causes the mastic to readily release its hold on the backing plate and peel off as the scraping blade is moved along. It is to be noted that since only the edge of the mastic is heated, the main portion of the mastic will be cool as it is peeled ofi. Thus, the operator will not be burned by contact with this material.

In Figures 4 and a modified scraping tool is illustrated including a base member 58 and a cover 5| secured to the base by countersunk setscrews 52. The base member 50 includes the bottom, front, rear and side walls of the casing defining a cavity 53 in which a heating element 55 is disposed.

It will be understood that the heating element 55 is identical to the element 33 previously described and is energized through leads 5? and 58 in an identical manner. The scraping tool of Figures 4 and 5 has arm members 6L1 identical to the arms 12 of Figure 3.

This modification features a casing including a base member 50 and a cover 5| that may be made of the same heat conducting material. The base 50 may advantageously be a one-piece cast- 4 ing having a central cavity. This modification also features a blade insert 59 which may be suitably secured in the base 50. This insert may be made of a special wear-resisting material that will stand up well under the scraping action.

A third embodiment of the scraping tool of the present invention is illustrated in Figures 6 and 7. This modification features a casing 60 including an upper half portion GI and a lower half 52 secured together by any suitable means, as by capscrews 63. Each half is hollowed out so that when assembled together they define a cavity 64 in which is positioned a core 65. This core 65 is constructed of a heat conducting material and has a central cavity 61 which receives a heating element 68 in close fitting contact.

The element 68 is energized through leads I0 and H which are connected into a male electrical connector 12. This connector 12 is retained in a groove 13 in the casing til having two prong memoers l5 pro ecting through an opening at the rear of the casing for receiving the female portion of the connection.

A ledge It extends from the forward portion of the core 65 exteriorly of the casing Bl]. A scraping blade l8 of wear resistant metal is secured on this ledge by a removable core portion 79 and a bolt 80 which passes ireely through an aperture 8| in the core portion 19 and is threaded into a nut 82 in an opening 84 in the ledge H5.

Thus there is provided in this embodiment a removacle made that is heated through the heating element 58 and the core E5. The casing 60 is of a convenient size for manual manipulation.

In order to prevent the casin from becoming hot, several annular recesses 86 are provided in the interior of the casing around the element 58. As a result the element contacts the casing only at a few guide shoulders and in a retaining groove 88. The casing Bl] may be made of any insulating material such as a heat resistant plastic. Air ventilation passages 89 are also provided in the casing 60.

From the foregoing description it will be seen that there is provided in this invention a simple, efiicient scraping tool by which heat may be applied to two adhesively secured materials at the point of bonding simultaneously with the application of the scraping blade.

The use of this tool is advantageous for a number of reasons. Since open flames are not employed and the mastic is not heated to combustion temperatures, fire hazards are eliminated and noxious fumes are avoided. The scrapings are cool as they leave the tool, hence the possibility of skin burns is greatly reduced. Finally, greater efficiency is attained since only a portion of the mastic need be heated, namely, the mastic that is immediately adjacent the metal surface.

It will be understood that modifications and variations may be effected Without departing from the scope of the novel concepts of the present invention. For example, a particularly useful modification of the device shown in Figures 4 and 5 comprises the use of a heating element 55 that is smaller than cavity 53. The heatin element is positioned against the bottom wall of the cavity and the remaining space is filled with insulation. This arrangement reduces radiation losses and tends to drive more of the heat into the blade.

I claim as my invention:

A scraping tool comprising an insulated housin having an elongated chamber extending therethrough and an annular groove in the inner wall of said chamber, a core member of heat conducting material in said housing having a flange portion retainingly engaged in said groove in said housing, a heating element in said housing having a flange locked between said core and said housing and an elongated portion in contact with said core, and a blade removably secured on said core and projecting exteriorly of said housing.

WILLIAM G. STOLK. References Cited in the file of this patent UNITED STATES PATENTS Name Date Chandler July 25, 1916 Number Number 1 [0 Number Name Date Chandler May 29, 1917 McNeil June 9, 1931 Peters Sept. 1, 1931 Coifelt Mar. 10, 1936 Peterson Dec. 1, 1936 Morris Nov. 18, 1941 Engesser Dec. 8, 1942 FOREIGN PATENTS Country Date France Jan. 16, 1939 

